Fixed #973
Merge pull request #989 from dvvrd/robots

Fixed #987
Merge pull request #990 from dvvrd/fix973

Fixed #973
- "равно" value removed from DistanceSign enum, as in real world equality is almost impossible
- added DistanceSign to encoders
Merge branch 'master' of https://github.com/qreal/qreal into #976
removing of graphical element from part model when it is removed from graphical model, fixes #984
clearing id positions hash, fixes #988
product version changed to 2.4.0
Merge pull request #994 from qreal/version

product version changed to 2.4.0
Merge pull request #993 from qreal/#988

clearing id positions hash, fixes #988
Merge pull request #991 from qreal/#976

#976
unit tests build fixed
Merge pull request #992 from qreal/#984

removing of graphical element from part model when it is removed from gr...